[David Ellis]

for my curiosity, why did you choose to design a B-version?

Both the 1801F and stand mounted 1801 are the "B" version with the same crossover.  The explanation for the B version is here:  

http://www.ellisaudio.com/1801bchanges.htm

Do you think that bookshelfs are as good/better than column versions (with same drivers and equivalent volume)?

All of these comments are mentioned previously.  My summary is... the quality of sound is the same.

Dave